Safely delivering breathable air to divers in a cold water environment presents challenges. Pressure regulators for underwater breathing convert high pressure gas to a lower pressure that are at or closer to a pressure that can be breathed by the diver.
First stage reduction of suitable gas for breathing typically incorporates pressure compensation for adjusting the pressure of the gas output from the pressure regulator based on the depth of the diver within the water. As a diver goes deeper in the water, the pressure compensation will increase the pressure of the gas being output from the regulator.
To provide pressure compensation, many regulators include a pressure compensation chamber that receives and fluidly communicates with the water surrounding the diver, and particularly the regulator. The water within the pressure compensation chamber will act on a moving mechanism that is biased in one direction by a spring and the ambient water and biased in an opposite direction by the gas being regulated and output by the regulator. As the surrounding water pressure increases, the force of the water on the moving mechanism also increases which creates an increased output pressure of the gas exiting the pressure regulator.
Unfortunately, the process of reducing the pressure of the gas from the inlet pressure to the outlet pressure is an adiabatic process that absorbs heat energy from the surrounding environment, namely the surrounding water.
In cold water dives, the temperature of the water can be near freezing. The adiabatic process of the pressure regulator can result in localized freezing of the surrounding water on the exposed surfaces of the regulator. If the water within the pressure compensation chamber freezes, the ice can affect the motion and operation of the moving mechanism and the spring.
The present invention seeks to provide improvements over the current state of the art of underwater pressure regulators for underwater breathing devices.